데이터 구조 일원 다항식 더하기

#include 
using namespace std;

//          
typedef struct Node
{
    int coe;    //  
    int exp;    //  
    Node *next;
}*polynomial;
//         
bool InitPoly(polynomial &L)
{
    L = new Node;
    if(!L)
        return false;
    L->next = NULL;
    return true;
}
//        
void CreatePoly(polynomial &L, int n)
{
    polynomial s, r;
    r = L;
    while(n--)
    {
        int i = 1;
        s = new Node;
        cout << "   " << i << "       :";
        i++;
        cin >> s->coe;
        cin >> s->exp;
        s->next = NULL;
        r->next = s;
        r = s;
    }
}
//       
polynomial AddPoly(polynomial pa, polynomial pb)
{
    polynomial s;   //     
    polynomial r;   //     
    s = new Node;   //           
    s->next = NULL;
    r = s;
    pa = pa->next;  //      
    pb = pb->next;
    while(pa && pb)
    {
        if(pa->exp > pb->exp)
        {
            r->next = pb;
            r = pb;
            pb = pb->next;
        }
        else if(pa->exp < pb->exp)
        {
            r->next = pa;
            r = pa;
            pa = pa->next;
        }
        else
        {
            int sum = pa->coe + pb->coe;
            if(0 != sum)
            {
                pa->coe = pa->coe + pb->coe;
                r->next = pa;
                r = pa;
            }
            pa = pa->next;
            pb = pb->next;
        }
    }
    if(NULL != pa)
        r->next = pa;
    if(NULL != pb)
        r->next = pb;
    return s;
}
//        
void PutPoly(polynomial L)
{
    polynomial p;
    p = L->next;
    while(p)
    {
        cout << "(" << p->coe << "," << p->exp << ")" << '\t';
        p = p->next;
    }
    cout << endl;
}
int main()
{
    polynomial pa, pb;
    InitPoly(pa);
    InitPoly(pb);
    cout << "     a   :";
    int n;
    cin >> n;
    CreatePoly(pa, n);
    cout << "     b   :";
    cin >> n;
    CreatePoly(pb, n);
    cout << "a+b     :";
    PutPoly(AddPoly(pa, pb));
    return 0;
}